Hello 'bettanychris',
No one here can fix your problems as these are member-to-member boards for ordinary users just like yourself.
I'm not sure how you managed to buy 2 of something when you only wanted one, but in future you will want to take extra care to not get carried away with clicking. It seems it is easier to make mistakes if using a hand-held device for shopping instead of a real computer.
If your seller has not responded, it may be that he has his listings set up to file automatic Unpaid Item cases against nonpayers as soon as the system allows. That is no excuse for ignoring you, but it happens.
Assuming you do not have any other Unpaid Item cases against you, the worst that will happen if you do not pay is you will get a strike on your account. If you get a second one you will find it difficult to bid and buy, as most sellers have an auto-block on anyone with 2 or more of these strikes.
If your seller is not responding, your choices are to pay for the item, or weather the storm.
The following link will tell you all about ebay's unpaid item policy:
http://pages.ebay.ca/help/policies/unpaid-item.htm